1. Field of the Invention
The present invention relates to a novel antimicrobial agent which is prepared by using a copolymer derived from, for example, a spent resin, and to a production process of the antimicrobial agent.
2. Description of the Related Art
Antimicrobial agents for suppressing the growth of bacteria and/or fungi include inorganic antimicrobial agents, organic antimicrobial agents extracted from natural products, organic antimicrobial agents composed of aliphatic compounds, and organic antimicrobial agents composed of aromatic compounds.
Such inorganic antimicrobial agents include, for example, sodium hypochlorite, and other chlorine compounds; hydrogen peroxide, and other peroxides; boric acid, sodium borate, and other borate compounds; copper sulfate, and other copper compounds; zinc sulfate, zinc chloride, and other zinc compounds; sulfur, calcium polysulfate, sulfur hydrate, and other sulfur substances; calcium oxide, and other calcium compounds; silver thiosulfite complex, silver nitrate, and other silver compounds; as well as iodine and sodium silicofluoride.
The organic antimicrobial agents extracted from natural products include, but are not limited to, hinokitiol, Phyllostachys pubescens extract, and creosote oil.
The organic antimicrobial agents composed of aliphatic compounds include, but are not limited to, tributyltin oxide, and other organotin compounds; copper naphthenate, and other cyclopentane derivatives; methyl bromide, and other halides; ethyl alcohol, isopropyl alcohol, and other monohydric alcohols; 2-bromo-2-nitro-1,3-propanediol, and other dihydric alcohols; formaldehyde, glutaraldehyde, and other saturated aldehydes; sorbic acid, potassium sorbate, and other carboxylate compounds; ethylene oxide, propylene oxide, and other ether compounds; beta-oxypropiolactone, and other lactone compounds; 3-trimethoxysilylpropyldimethyloctadecylammo-nium chloride, and other quaternary ammonium salt compounds; di(octylaminoethyl)glycine hydrochloride, and other amino acid derivatives; sodium lauryl sulfate, and other sulfonic acid compounds; bisdequalinium acetate, and other hydroxamic acid compounds; isocyanuric chloride, and other cyanuric acid compounds; methyl isocyanate, and other cyanic acid compounds; bis(trichloromethyl)sulfone, and other sulfone compounds; polyhexamethylenebiguanidine hydrochloride, and other guanidine compounds; 1,3-dichloro-5,5-dimethylhydantoin, and other hydantoin compounds; 5-oxy-3,4-dichloro-1,2-dithiol, and other dithiol compounds; iron methylarsinate, and other arsine compounds; tris(ethylphosphate)aluminium, and other phosphate compounds; and thiocarbamide compounds.
The organic antimicrobial agents composed of aromatic compounds include, but are not limited to, bis(4-nitrophenyl) carbonate, and other carbonate compounds; benzalkonium chloride, benzethonium chloride, and other quaternary ammonium salt compounds; 2,6-dichloro-4-nitroaniline, and other monoamine compounds; potassium nitroethylbenzylethylenediamine, and other diamine compounds; aluminium N-nitroso-N-cyclohexylhydroxylamin-e, and other hydroxylamine compounds; dihydromethyloxathiinecarboxanilide dioxide, and other anilide compounds; 2-(4-thiazolyl)benzimidazole, and other imidazole compounds; 5-methyl-1,2,4-triazol-3,4-benzothiazole, and other benzothiazole compounds; 2,4-dichloro-6-chloroanilino-1,3,5-triazin-e, and other triazine compounds; chlorhexidine hydrochloride, chlorhexidine gluconate, and other guanidine compounds; cetylpyridinium chloride, and other pyridine compounds; dimethylpyrazolylhydroxyphenylpyr-imidine, and other pyrimidine compounds; 2,2′-methylenebis-3,4,6-trichloro-phenol, and other halogenobenzene compounds; copper hydroxynonylbenzenesulfonate, and other benzenesulfonate compounds; benzoic acid, and other benzenecarboxylic acid compounds; thimerosal, and other mercaptocarboxylic acid compounds; ethyl hydroxybenzoate, and other hydroxycarboxylic acid compounds; phenol, cresol, and other monohydric phenol compounds; resorcinol, and other dihydric phenol compounds; phenoxyethanol, and other phenoxy ether compounds; pentachlorophenyl laurate, and other phenol ester compounds; triphenyltin oxide, and other phenyl compounds; diphenyl, and other biphenyl compounds; beta-naphthol, and other monohydric naphthols; monochloronaphthalene, and other naphthalene compounds; dodecylisoquinolinium bromide, and other isoquinoline compounds; as well as nitrile compounds, isothiazole compounds, thiadiazole compounds, halogenophenol compounds, pyrrole compounds, quinone compounds, quinoline compounds, and organic phosphoric ester compounds.
However, there has been no antimicrobial agent using an ABS resin, or another resin, whereas the above types of antimicrobial agents are typically used. Resins each containing acrylonitrile and styrene and/or a conjugated diene are classified as polystyrenic resins such as ABS resins, SAN resins, and AAS resins, and as synthetic rubbers such as NBR rubbers. These resins are relatively low in cost. Particularly, the former polystyrenic resins are excellent in rigidity, dimensional stability, workability, and other properties and are widely used as materials for covers and casings for various applications, housings, and other parts of electric equipment and automobiles, and as other resinous materials. The latter synthetic rubbers are widely used as tubes, hoses, and various cushioning materials.
Under these circumstances, these materials are expected to be used in further broader applications and demands are made to improve these materials to those having higher added values. In other words, these materials are now used in the aforementioned applications alone and are not used as antimicrobial agents.
Additionally, products obtained by using the above resins yield a large quantity of spent resins as discarded materials with an increasing production. The amount of discarded materials composed of these materials tends to increase in recent years, and there are increasing demands to make effective use of such discarded materials from the viewpoint of global environmental conservation.